Apparatus for agitation of concrete



Mmh 27, 1934. H B, NE 1,952,922

APZARATUS FOR AGITATION OF CONCRETE Filed May 4. 1931 2 Sheets-Sheet l WWII March27, 1934. H. B. JONES APPARATUS FOR AGITATION OF CONCRETE Filed. May 4. 1951 2 Sheets-Sheet 2 Patented Mar. 27, 1934 APPARATUS FOR AGITATION OF CONCRETE Harry Bernard Jones, Chicago, 111., assignor to National Equipment Corporation, Milwaukee,

Wis., a corporation Application May 4, 1931, Serial NO. 534 948" Claims.

This invention appertains to mixing or agitating machines for transportation of concrete from central mixing or batching plants to the site of deposit or use of the aggregate materials.

Such machines are usually trucks equipped with so called transit mixer or agitator bodies,

these bodies being of drum-like form and adapted to mix the concrete, in transit if desired, or at the place where it is to be deposited; or in the case of the agitator body, the action of the drum or body is mainly one of maintaining the concrete materials in agitation even if they have been mixed, so that segregation will not take place en route.

The present invention relates to such types of transporting machines and is designed to mainmounted either upon a truck or stationarily for mixing a charge of concrete or similar aggregates.

The invention has for a further object the provision of such a mixing drum wherein instrumentalities are provided for markedly increasing the mixing action of the drum.

A still further object of the invention is to provide a polyhedral mixing drum formed of a number of panels defining the sides of the drum, the angles between these panels causing the charge in the drum to be carried up and thrown over during rotation of the drum, thereby materially assisting in preventing segregation of the aggregates and. producing a uniform mix.

Briefly outlined, the invention also contemplates the use of a transit mixer wherein there is employed a mixing barrel or drum of a shape having amixing body formed of twelve or any suitable number of sides or panels. This drum is structurally provided with a charging opening at the top and a discharge opening at one end of the drum, the other end being closed and preferably flat. Within the drum is provided a plurality of spirally directed blades, some with bucket ends, progressively spaced on the inside of the container and terminating adjacent the opening through which the material is to be discharged. The drum isrotatably mounted and is driven by a suitable source of power whichis either the engine of the truck, or a separate engine, whichever is found to be more convenient. In practice, it is usually desirable for purposes of convenience to utilize a second or auxiliary engine for purposes of driving the drum. Material charged into the falls upon these spiral blades, and as the drum. is rotated in one direction, for example in a clockwise direction, depending upon the direction of the spiral of the blades, the charged aggregates will be directed toward the closed end of the drum, near which closed end may also be provided blades positioned between theaforesaid spiral blades and the axis of the drum and positioned in a direction opposite to that of'the' spiral blades to there'- by cause a back-flow of the aggregates around the central axis and in the opposite direction to that produced by the action of the spiral blades. It will thus be seen that a very eflicient mixing ac}- tion is obtained. The spiral blades are of special, novel form, each blade having an edge overturned to provide a discharge chute for directing the mixed aggregates through the discharge opening of the drum.

By rotating the drum in an opposite direction, the spiral blades will convey the aggregates toward the discharge opening and upon opening the cover provided for this opening, the mixed aggregates will be dischargedfrom the drum out any necessity of tilting the drum, complete emptying thereof being accomplished solely through the action of these spiral blades;

By providing a water tank on the trunk adjacent the drum and by placing in this tank a predetermined quantity of water dependent upon the amount for combination with the aggregates being mixed, it will be apparent that the proper mixture of water with the aggregates'can be obtained while the mixer is in transit from the tral mixing plant. A feature of novelty of this water tank may be introduced by dividing this tank into a plurality of compartments, one of which contains the water for mixing with the aggregates, another for containing water for use in washing out the mixing drum when the charge thereof has been discharged, and a third, for'example, to contain a supply of fuel' such as gasolene for the source of power which drives the drum. The water compartments are controlled, as will be obvious, by a suitable valve system, as will be described in more detail hereinafter.

While the invention as illustrated in the accompanying drawings represents a twelve-sided mixing drum, it will be apparent that the invention is not limited to a drum of such configuration, the purpose of the invention beingv independent of any specific shape of this mixing drum.

In these drawings Figure 1 is a side elevation of a truck provided with a mixing drum and auxiliary agent therefor, which drum is constructed in accordance with this invention.

Figure 2 represents a longitudinal section through the mixing drum, showing details of the interior construction thereof.

Figure 3 is a view similar to Figure 2, the drum having been located at right angles to the showing of Figure 2.

Figure 4 is a sectional view taken on the line 44 of Figure 2, looking in the direction of the arrows.

Figure 5 is a sectional view on the line 55 of Figure 3, looking toward the discharge end of the drum in the direction of the arrows.

Figure Sis a diagrammatic sectional view of a tank conveniently usable in connection with the novel mixing drum.

Referring more particularly to the drawings, it will be seen that the drum A is mounted upon 'a sub-frame B carried on the truck C. The drum A is conveniently shaped, as shown, as being made up of a cylindrical type container desirably of a polyhedral configuration rotatably mounted on an axis approximately about its horizontal center. One end of the container is closed and rounded, the other end 11 being provided with a discharge opening and closure therefor, the aforesaid end 10 being centrally flattened to receive a water line 12 for admission of water to the interior of the drum from the tank 13 mounted adjacent to the drum. This water line may, of course, be omitted if desired, as for example, when premixed concrete is to be handled, when addition 'of water will not be required.

It will also be seen that the drum A is rotatably mounted upon the sub-frame B, for this purpose there being provided the gear 14 meshed with the ring gear 15 on the drum and being driven through the shaft 16 from a suitable source of power, such as the engine 17. Adjacent the discharge end 11 of the drum, are mounted rollers 18 engaging the surface 19 carried by the drum and serving as a bearing surface for the rollers 18. It will of course be apparent that the drum can be rotated either clockwise or counter-clockwise, as desired.

Interiorly of the drum are mounted the spirally disposed blades 20 and 21, which are secured 'to the drum in any suitable manner, and extend from the discharge end 11 to a point adjacent "the flattened closed end 10, these blades being so directed that aggregates charged by gravity into the drum into the charging hopper indicated at 22 will fall upon these spiral blades and be directed toward the closed end of the drum. The blades 20 and 21 have their edges turned, as indicated at 20a and 21a, to provide scoops or chutes for directing the mixed charge from the drum; or, instead of the edges of the blades being turned, separate scoop members may be employed to cooperate with the blades, which scoop mem- ;bers are positioned with the same slope as the blades.

. As previously mentioned, blades 23 and 24 act in a direction opposite to the spiral blades 20 and 21 so that the aggregates being conveyed by the blades 20 and 21 toward the closed end 10 ofythe drum will be sent backward against the action of these blades 20 and 21 through the action of the blades 23 and 24, thus facilitating the thorough agitation and mixing of the charge.

It will be observed that by opening the discharge opening 25 and rotating the drum in an opposite direction, the spiral blades 20 and 21 will direct the charge of mixed aggregates outwardlythrough the opening 25, thus discharging the drum without necessitating any tilting, this action being greatly facilitated by the scoops 20a and 21a at the region adjacent the discharge opening 25, as will be very apparent from Figure 4.

Instead of the blades 20 and 21 extending unbrokenly throughout the drum, they are separated about midway of their length and disposed in overlapping relation, as will be seen in Figures 2 and 3, the portion 21b illustrating the separated, off-set portion of the blade 21, it being understood that there is a similar provision for the blade 20, which is notshown in the sections represented by Figures 2 and 3. This separation facilitates the mixing action as the material is dropped from the overlapped portion of each blade on to the other as the drum rotates, instead of being conveyed evenly along.

The action of the spiral blades 20 and 21 is to cause the aggregates to move in a longitudinal direction progressively through the drum, while releasing the aggregates to drop transversely of the drum. This action obviously very substantially increases the mixing action and proceeds until the aggregates reach the scoops 20a and 21a for discharge from the drum. These scoops discontinue the mixing and convert the movement of the aggregates into a longitudinal movement entirely for the discharge thereof.

It will be noted that the blades 23 and 24 are carried upon the shaft 26, or they may be carried upon brackets attached to the drum, as indicated at 23a and 24a. The shaft 26 is a pipe permitting the introduction of water from the tank 13 into the interior of the drum, although, as previously mentioned, this pipe 12 may be omitted. In Figure 3, the brackets 23a and 24a are omitted, and it will be understood that in the event pipe 12 is omitted, these brackets will be secured tothe drum driving gear 14 and engine 1'7, there is provided a universal joint, illustratedat 26, posi: tioned in the power transmitting shaft.

The charging opening 22 is conveniently located about midway along the wall of the drum and is fitted with a cover 27, which seals the opening air-tight, the aggregates discharged through this opening falling by gravity on the spiral scoop blades 20, 21, and 21b, for ready mixing, as has hereinbefore been described. The discharge port 25 is also provided with an airtight closure member indicated at 28 on Figure 1, operable in any well known convenient manner for sealing the port.

For the convenience of an attendant, a platform indicated at 29 may be provided at each side of the drum.

If desired, a counting means for counting the number of revolutions made by the barrel during the mixing operation may be utilized in the well known manner for indicating the number of revolutions, and in order to assure the mixing drum stopping with its charge port 22 vertically disposed, suitable braking instrumentalities for arresting the rotation of the drum may also be provided. Both of these means are well known standard constructions, and form no part of this invention, and accordingly have not been illustrated.

As will be seen from Figure 6, the tank 13 is divided into a plurality of compartments. Compartment may contain a predetermined quantity of mix water, compartment 31, a volume of water to be utilized in washing out the mixing drum A after the drum has been discharged, and compartment 32 contains the supply of fuel for the engine 17, this fuel being conveniently, of course, gasolene, introduceable into the engine through the line 33. The compartments 30- and 31 are illustrated as being interconnected by the pipe 34 and controlled by valves 35 and 36 by means of which valves water may be introduced into the drum A through the line 12 and pipe or shaft 26.

It will be apparent that many changes in the details of the construction herein specifically illustrated and described may be made without departing from the inventive concept, and it will accordingly be understood that it is intended and desired to embrace within the scope of this invention such modifications and changes as may be necessary to adapt it to varying conditions and uses.

As previously mentioned, the configuration of the drum markedly increases the effectiveness of the mixing operation, since the panels forming the sides of the drum produce increased Wave motion throughout the charge, and the angles between the sides cause the charge to be carried up and thrown over during the rotation of the drum.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is

l. A concrete mixing machine comprising the combination with a mixing drum, of means within the drum for mixing a charge of aggregates and for feeding the said aggregates through the drum while being mixed, the said means comprising a plurality of cooperating spiral blades mounted on the inner periphery of the drum and extending substantially completely through the drum, one edge of certain of the blades being overlapped to form a scoop, and means for counteragitating the aggregates as the charge thereof passes through the drum, the counter-agitating means comprising blades counter-inclined with reference to the spiral blades and receiving the aggregates from the spiral blades upon actuation thereof in one direction, the spiral blades serving to discharge the mixed aggregates from the drum upon actuation in the reverse direction.

2. A concrete mixing machine comprising the combination with a rotatably mounted mixing drum, of means within the drum for mixing a charge of aggregates and for feeding the said aggregates through the drum while being mixed, the said means comprising a plurality of cooperating spiral blades mounted on the inner periphery of the drum and extending substantially completely through the drum, and blades within the drum counter-inclined with reference to the spiral blades for receiving the aggregates from the spiral blades as the drum is rotated in one direction to thereby counter-agitate the aggregates to assure thorough mixing thereof, the spiral blades serving to discharge the mixed aggregates from the drum upon rotation of the drum in the reverse direction.

3. In a concrete mixing machine, a rotatably mounted non-tilting mixing drum having its axis disposed in a substantially horizontal plane, said drum having a closed end and openable discharge end, a plurality of blades spirally positioned with in the drum around its rotary axis and secured to the inner wall of the drum, said blades being widened adjacent the discharge end of thedrum and recurved on themselves along their'inner edges to form inclined discharge chutes, extending inwardly of the drum and inclining toward the central axis and the open end of said drum.

4. A rotary mixing drum for a concrete mixer having an open discharge end portion, a plurality of spiral mixing and discharge blades arranged within the drum, said blades extending inwardly toward the longitudinal axis of the drum adjacent the discharge end of the drum, inclined discharge scoops disposed on the free inner portion ofthe spiral blades, said discharge scoop portions inclining rearwardly toward the discharge end and the axis of the drum and terminating adjacent the axis of the drum, said discharge scoop portions receiving the material being mixed from the spiral blades and conveying the material outwardly of the drum and discharging the same at points spaced from the side of the drum upon rotation of the drum.

5. In a concrete mixing machine of the class described an elongated rotary mixing drum disposed on a substantially horizontal axis, said drum having a closed end and an openable discharge end, spiral mixing and discharging blades secured to the interior surface of the drum and extending substantially radially inwardly and spirally around the longitudinal axis thereof to the discharge end, cooperating inclined transversely curved rotary discharge scoops interiorly of the spiral blades and in spaced relation to the interior surface of the drum adjacent the discharge end portion for receiving the material directly from the spiral blades and conveying the material to discharge points substantially centrally of the discharge opening.

6. In a concrete mixing machine, a rotatably mounted non-tilting mixing drum having its axis disposed in a substantially horizontal plane, said drum having a closed end and openable discharge end, a plurality of blades spirally positioned within the drum around its rotary axis and secured to the inner wall of the drum, said blades being widened adjacent the discharge end of the drum and recurved on themselves adjacent their inner edges to form inclined discharge chutes, extending inwardly of the drum and inclining toward the central axis and the open end of said drum, said chutes being curved substantially threefourths cylindrical in cross-section.

7. A concrete mixer comprising an elongated mixing drum mounted with its longitudinal axis secured in a horizontal plane, the drum being closed at one end and provided with a port at its other end, and spirally arranged mixing instru- 135 mentalities arranged Within the drum to convey a charge of aggregates away from the port and towards the closed end of the drum upon actuation of the instrumentalities in one direction to completely agitate and mix the aggregates and 140 to convey the mixed aggregates through the port to discharge the drum upon reverse actuation of said spirally arranged instrumentalities, said spirally arranged instrumentalities being formed with spaced offset discharge chute sections 145 trough-shaped in cross section and spaced inwardly from the interior surface of the drum adjacent the discharge port.

8. A concrete mixing machine comprising an elongated mixing drum closed at one end and provided with a port at its other end, said drum having a longitudinal axis and spirally disposed blades arranged concentrically of the longitudinal axis of the drum from the port end to adjacent the closed end, the blades being inwardly sloped adjacent the port and having the inner portion thereof formed into inclined discharging scoops, one end of said scoops terminating adjacent the longitudinal axis of the drum, for discharging a charge of material through the port upon rotation of the spiral blades in one direction.

9. A concrete mixing machine comprising an elongated mixing drum closed at one end and provided with a port at its other end, spirally disposed mixing and conveying blades extending from adjacent the port end to adjacent the closed end, the blades being broken in their continuity, and auxiliary mixing blades mounted concentrically within said spiral blades and inclined in opposition to the adjacent spiral blades, the spiral blades extending around the inner periphery of the drum and projecting inwardly of the drum and recurved on themselves at their inner edges to form longitudinally extending spaced scoops adjacent the port for directly discharging the drum of its contents upon rotation of the spiral blades in one direction.

10. A concrete mixing machine comprising a rotatably mounted non-tiltable panelled mixing drum having charging and discharging ports therefor, and conveying and mixing instrumentalities within the drum for mixing aggregates upon rotation of the drum in one direction and for discharging the mixed aggregates from the drum upon rotation thereof in the reverse direction, the said mixing instrumentalities comprising spiral blades having a portion thereof adjacent the discharge port formed into inwardly inclined discharge scoops trough-shaped in cross section and spaced from the wall of the drum for directing the material within the drum outwardly through the discharge port.

HARRY BERNARD JONES. 

